On 2023-04-11 15:44, Daniel Vetter wrote:
On Tue, Apr 04, 2023 at 09:39:34PM +0200, Daniel Vetter wrote:This is an oversight from dc5bdb68b5b3 ("drm/fb-helper: Fix vt restore") - I failed to realize that nasty userspace could set this. It's not pretty to mix up kernel-internal and userspace uapi flags like this, but since the entire fb_var_screeninfo structure is uapi we'd need to either add a new parameter to the ->fb_set_par callback and fb_set_par() function, which has a _lot_ of users. Or some other fairly ugly side-channel int fb_info. Neither is a pretty prospect. Instead just correct the issue at hand by filtering out this kernel-internal flag in the ioctl handling code. Signed-off-by: Daniel Vetter <[email protected]> Fixes: dc5bdb68b5b3 ("drm/fb-helper: Fix vt restore") Cc: Alex Deucher <[email protected]> Cc: [email protected] Cc: Michel Dänzer <[email protected]> Cc: Noralf Trønnes <[email protected]> Cc: Thomas Zimmermann <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Maarten Lankhorst <[email protected]> Cc: Maxime Ripard <[email protected]> Cc: David Airlie <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: [email protected] Cc: <[email protected]> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Qiujun Huang <[email protected]> Cc: Peter Rosin <[email protected]> Cc: [email protected] Cc: Helge Deller <[email protected]> Cc: Sam Ravnborg <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Shigeru Yoshida <[email protected]>An Ack on this (or a better idea) would be great, so I can stuff it into -fixes.
Acked-by: Maarten Lankhorst <[email protected]>
